/*
 * URLContent.java 25 avr. 2006
 *
 * Sweet Home 3D, Copyright (c) 2006 Emmanuel PUYBARET / eTeks <info@eteks.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package com.eteks.sweethome3d.tools;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;

import com.eteks.sweethome3d.model.Content;

/**
 * URL content for files, images...
 * @author Emmanuel Puybaret
 */
public class URLContent implements Content
{
	private static final long serialVersionUID = 1L;
	
	private URL url;
	
	public URLContent(URL url)
	{
		this.url = url;
	}
	
	/**
	 * Returns the URL of this content.
	 */
	public URL getURL()
	{
		return this.url;
	}
	
	/**
	 * Returns an InputStream on the URL content. 
	 * @throws IOException if URL stream can't be opened. 
	 */
	public InputStream openStream() throws IOException
	{
		URLConnection connection = getURL().openConnection();
		if (OperatingSystem.isWindows() && isJAREntry())
		{
			URL jarEntryURL = getJAREntryURL();
			if (jarEntryURL.getProtocol().equalsIgnoreCase("file"))
			{
				try
				{
					if (new File(jarEntryURL.toURI()).canWrite())
					{
						// Even if cache is actually not used for JAR entries of files, refuse explicitly to use 
						// caches to be able to delete the writable files accessed with jar protocol under Windows, 
						// as suggested in http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6962459 
						connection.setUseCaches(false);
					}
				}
				catch (URISyntaxException ex)
				{
					IOException ex2 = new IOException();
					ex2.initCause(ex);
					throw ex2;
				}
			}
		}
		return connection.getInputStream();
	}
	
	/**
	 * Returns <code>true</code> if the URL stored by this content 
	 * references an entry in a JAR.
	 */
	public boolean isJAREntry()
	{
		return "jar".equals(this.url.getProtocol());
	}
	
	/**
	 * Returns the URL base of a JAR entry.
	 * @throws IllegalStateException if the URL of this content 
	 *                    doesn't reference an entry in a JAR.
	 */
	public URL getJAREntryURL()
	{
		if (!isJAREntry())
		{
			throw new IllegalStateException("Content isn't a JAR entry");
		}
		try
		{
			String file = this.url.getFile();
			return new URL(file.substring(0, file.indexOf('!')));
		}
		catch (MalformedURLException ex)
		{
			throw new IllegalStateException("Invalid URL base for JAR entry", ex);
		}
	}
	
	/**
	 * Returns the name of a JAR entry. 
	 * If the JAR entry in the URL given at creation time was encoded in application/x-www-form-urlencoded format,
	 * this method will return it unchanged and not decoded.
	 * @throws IllegalStateException if the URL of this content 
	 *                    doesn't reference an entry in a JAR URL.
	 */
	public String getJAREntryName()
	{
		if (!isJAREntry())
		{
			throw new IllegalStateException("Content isn't a JAR entry");
		}
		String file = this.url.getFile();
		return file.substring(file.indexOf('!') + 2);
	}
	
	/**
	 * Returns <code>true</code> if the object in parameter is an URL content
	 * that references the same URL as this object.
	 */
	@Override
	public boolean equals(Object obj)
	{
		if (obj == this)
		{
			return true;
		}
		else if (obj instanceof URLContent)
		{
			URLContent urlContent = (URLContent) obj;
			return urlContent.url == this.url || urlContent.url.equals(this.url);
		}
		else
		{
			return false;
		}
	}
	
	@Override
	public int hashCode()
	{
		return this.url.hashCode();
	}
}
